Improve invalid file path type diagnostics

Co-authored-by: Shri Sukhani <shrisukhani@users.noreply.github.com>

Author: cursoragent

hyperbrowser/client/file_utils.py

@@ -11,7 +11,13 @@ def ensure_existing_file_path(
     missing_file_message: str,
     not_file_message: str,
 ) -> str:
-    normalized_path = os.fspath(file_path)
+    try:
+        normalized_path = os.fspath(file_path)
+    except TypeError as exc:
+        raise HyperbrowserError(
+            "file_path must be a string or os.PathLike object",
+            original_error=exc,
+        ) from exc
     if not os.path.exists(normalized_path):
         raise HyperbrowserError(missing_file_message)
     if not os.path.isfile(normalized_path):

tests/test_file_utils.py

@@ -50,3 +50,14 @@ def test_ensure_existing_file_path_raises_for_directory(tmp_path: Path):
             missing_file_message="missing",
             not_file_message="not-file",
         )
+
+
+def test_ensure_existing_file_path_rejects_invalid_path_type():
+    with pytest.raises(
+        HyperbrowserError, match="file_path must be a string or os.PathLike object"
+    ):
+        ensure_existing_file_path(
+            123,  # type: ignore[arg-type]
+            missing_file_message="missing",
+            not_file_message="not-file",
+        )